In recent years, public wireless LAN service has been performed in a wireless LAN system using a wireless system such as IEEE 802.11 (for example, ANSI/IEEE Std 802.11, 1999 Edition), and wireless Internet access environments have become widespread. In the communication service in such public wireless LAN service, a terminal principally accesses a server group existing on the Internet.
Meanwhile, as typified by IP telephone and push type service, Internet service has been implemented such that a server group accesses a terminal.
In the wireless LAN system, a mobile terminal only adopts a state that a wireless channel is always connected or a wireless channel is completely disconnected and a power supply of a wireless interface is turned off. However, connecting the wireless channel always results in power consumption. Accordingly, when a portable mobile terminal is applied as a terminal, the mobile terminal turns off the power supply of the wireless interface during a period of time communications are not performed constantly so as to extend the connection time. In other words, when a server group accesses such a mobile terminal, a communication channel of the mobile terminal is not connected unless the mobile terminal is communicating.
Further, when the communication channel of the mobile terminal is not connected, the server group cannot detect that the mobile terminal has moved, and therefore, cannot manage an IP address that is position information of the mobile terminal.
As described above, in the wireless access system using the wireless access system without the paging function, there is a problem that a server group cannot perform paging processing on a mobile terminal.